1560s, "one who shoes horses," from Middle French ferrier "blacksmith," from Latin ferrarius "blacksmith," noun use of adjective meaning "of iron," from ferrum "iron" (in Medieval Latin, also "horseshoe"); see ferro-. An earlier form of it in English was ferrer, ferrour "ironsmith" (late 12c. as a surname), from Old French ferreor, from Medieval Latin ferrator "blacksmith."